SPRITES AS LUMINOUS COLUMNS OF IONIZATION PRODUCED BY QUASI-ELECTROSTATIC THUNDERCLOUD FIELDS

Quasi-electrostatic (QE) fields which exist above thunderclouds after lightning discharges can lead to the formation of columnar channels of breakdown ionization and carrot-like vertical luminous structures wit h typical transverse dimension similar to 5-10 km spaning an altitude range from similar to 80 km to well below similar to 50 km. The carrot -like forms closely resemble those observed in sprites. Results indica te that the appearance of optical emissions can be significantly delay ed in time (similar to 1-20 ms) with respect to the causative lightnin g discharge.